Pumps, motors and like devices



Oct. 8, 1963 B. H. MOSBACHER 3,

PUMPS, MOTORS AND LIKE DEVICES 4 Sheets-Sheet 1 Filed April 4, 1960 f Oct. 8, 1963 B. H. MOSBACHER 3,106,163

PUMPS, MOTORS END LIKE DEVICES Filed April 4, 1960 4 Sheets-Sheet 2 I I x 64 e 2 .6

[ME/Ira? 6 Oct. 8, 1963 B. H. MOSBACHER 3,106,163

PUMPS, MOTORS AND LIKE DEVICES 4 Sheets-Sheet Filed April 4, 1960 inf/W00 B W 0am ATTOPMY 1963 B. H. MOSBACHER 3,

' PUMPS, MOTORS AND LIKE DEVICES Filed April 4, 1960 4 Sheets-Sheet 4 ByYhMMZ-JvE United States Patent Ofiice 3,106,163 Patented Oct. 8, 1963,

3,106,163 PUMPS, MOTGRS AND LIKE DEVICES Bruce H. Mosbacher, Rockford, Ill, assignmto- Roper Hydraulics, Inc., Commerce, Ga, a corporation of Georgia Filed Apr. 4, 1960, Ser. No. 19,727 14 Claims. (Cl. 103-2) This invention relates to improvements in pumps, motors and like devices of the internal gear type.

An important object of this invention is to provide an internal gear type pump or motor in which the outer gear is stationary and the inner gear moves in an orbital path relative to the outer gear to cyclically vary the volume of the pumping chambers between the inner and outer gears, and in which the inner gear valves the flows of fluid to and from the pump chambers in timed relation with the cyclic change in the volume of the pumping chambers.

Another object of this invention is to provide an internal gear type pump having a stationary outer gear and an inner gear which moves in an orbital path relative to the outer gear to cyclically vary the volume of the pumping chambers between the inner and outer gears, and in which the fluid flows to and from different ones of the pumping chambers are passed through separate flow passages to provide a multiple flow pump.

Still another object of this invention is to provide an internal gear type pump or motor having a stationary outer gear and an orbiting inner gear and having an improved arrangement for connecting the orbiting inner gear to a drive shaft.

A further object of this invention is to provide an improved pumping apparatus for use in a lubrication system to withdraw lubricant from a plurality of sumps, and to deliver the lubricant in separate streams to different outlets.

These, together with various ancillary objects and advantages of this invention will be more readily appreciated as the same becomes better understood from the following detailed description when taken in connection with the accompanying drawings wherein:

FIGURE 1 is a longitudinal sectional view through the pump or motor;

FIG. 2 is a transverse sectional view taken on the plane 22 of FIG. 1, and with the cam shaft angularly displaced 90 from the position shown in FIG. 1;

FIG. 3 is a transverse sectional view taken on the plane 3-3 of FIG. 1 and with the cam shaft angularly displaced 90 from the position shown in FIG. 1, and with the inlet and outlet ports shown in phantom;

FIG. 4 is a transverse sectional view taken on the plane 44 of FIG. 1;

FIG. 5 is a transverse sectional view taken on the plane 5-5 of FIG. 1 illustrating the inlet and outlet ports in the end wall of the housing and the path traced by one of the valve ports in the inner gear as the latter moves in an orbital path;

FIG. 6 is a diagrammatic view illustrating the layout of the preferred shape of the ports on the inner gear for maximum flow;

FIG. 7 is a side view of one of the inner gears with one side plate removed to show the passages therein;

FIG. 8 is a sectional view through a pump or motor device having a modified form of drive; and

FIG. 9 is a fragmentary sectional view taken on the plane 99 of FIG. 8.

A multiple element type pump or motor is illustrated in the drawings and includes first and second outer gears 19 and 11 respectively which are separated by a divider plate 12. A first head 13 is disposed at one end of the outer gear 11 and a second head 14 overlies the remote end of the other gear 10. The several parts are conveniently held together by studs 15 and O-rings '1'6 and 17 are provided in grooves in opposite faces of the outer gears 10 and 11 to seal the same to the adjacent elements. Inner gears18 and 19 are disposed within the outer gears 10 and 11 respectively and define a pumping chamber therebetween. The outer gears x16) and 11 have inwardly extending teeth designated 10a and 11a, and herein shown fifteen in number. The inner gears 18 and 19 each have one tooth less than the respective outer gears and, as shown, have fourteen teeth designated 18a and 1% respectively. As is conventional, the teeth on the inner and outer gears are shaped so that each of the teeth on the inner gear engages a respective one of the teeth on the outer gear, in all operative positions of the inner and outer gears, to separate the pumping chamber into a plurality of separate fluid displacement chambers. Since the outer gears 10 and 11 are stationary, the inner gear will move in an orbital path relative to the outer gear to cyclically vary the volume of the displacement chambers for-med between the teeth of the inner and outer gears. Each time the inner gear completes one orbit, the volume of each displacement chamber is varied through one cycle. Moreover, since the inner gear has one less tooth than the other gear, the inner gear will turn about its own axis through an angle corresponding to the angular spacing between adjacent teeth each time the inner gear is moved through a complete orbit relative to the outer gear. The turning of the inner gear is, however, in a direction opposite the direction of orbital movement of the inner gear. In accordance with the present invention, the orbital movement of the inner gear is utilized to effect valving of the flows of fluid to and from the fluid displacement chambers between the inner and outer gears, in timed relation with the cyclic variation of the volume in those chambers.

The apparatus illustrated in FIGS. 1-5 is specifically designed for use in a lubrication system to draw lubricant from a plurality of sumps, diagrammatically illustrated in FIG. 4 and designated 24, 25 and 246, and to deliver the fluid in separate streams to a plurality of outlet conduits 27. For convenience, the several ports and passages will :be designated inlet and discharge passages in accordance with the function they perform when used in conjunction with the disclosed lubrication system, it being understood that the inlet and discharge passages will function as discharge and inlet passages respectively, if the drive is reversed, and that, moreover, the device can be operated as a motor instead of a pump, if pressurized fluid is supplied to the apparatus. As best shown in FIG. 1, the inner gears 18 and 19 are connected to a drive shailt 31 journaled in bearings 32 and 33 in the heads 13 and.14 respectively. A shaft seal 35 is provided for sealing the interface between the shaft and the pump housing and is held in place by a seal clamp ring 36. The shaft 31 is disposed concentric with the outer gears 16 and 11 and has spaced eccentrics 38 and 39 thereon. The inner gear 18 is rotatably supported by a bearing 41 on the eccentric 38 and the inner gear IQ is supported by a bearing 42 on the eccentric 39. As the shaft is rotated by a suitable drive (not shown), the inner gears 18 and 19 move in the aforedescribed orbital path. As will be noted from FIG. 1, the eccentrics 38 and 39 are disposed out of phase so that one pump counterbalances the other. The head 13 has an annular inlet port 45 formed in the end face which abuts against the inner gear 19, and which inlet port communicates through passages 46 with an inlet chamber 47 formed in the head 13. An inlet passage 48, which is adapted for connection to an inlet conduit 49, communicates with the inlet chamber 47 to supply fluid thereto. The head 13 also has a plurality of annularly spaced outlet ports 51 [formed in the end face thereof against which the inner gear 19 abuts, and which outlet ports correspond in number to the number of teeth in the outer gear 11. The outlet ports 51 communicate through individual flow passages 52 with the respective outlet conduits 27 to provide segregated flows from the pump. The inner gear 19 has a plurality of rotor ports 55 therein which open at that end face of the inner gear which rubs against the head 13. Conveniently, the ports 55 may be in the form of holes which extend axially through the inner gear, to simplify the forming operation. With such an arrangement, the divider wall 12 forms a seal for the other end of the rotor ports. The rotor ports are annular-1y spaced apart and correspond in number to the number of teeth on the inner gear 19. As will be noted, the inlet and outlet ports 45 and 51 in the end wall of the head 13 are spaced radially from each other to provide a sealing land 56 therebetween and the rotor ports 55 are spaced radially from the axis of the inner gear a distance equal to the mean radius of the sealing land 56. The radial width of the valve ports 55 is preferably made slightly less than the radial width of the land 56 between the inlet and outlet ports so as to provide a seal between the inlet and outlet ports in all operative positions of the inner gear. For the purpose of simplifying the machining and fabrication of the pump or motor device, the ports 55 may be in the form of circular holes as shown in FIGS. 13. However, for maximum flow, the ports should have the some- What oblong shape designated 55' in FIG. 6. The port shown in FIG. 6 is twice the scale shown in FIGS. 1-3 and the point a designates the center of the outer ring gear and the points b and b represent the center of the inner gear at two points 180 out of phase with each other. As will be noted, the points b and b are spaced from the point a a distance e corresponding to the eccentricity between the inner and outer gears. The outer edges 58 of the port 55' correspond to arcs having a radius equal to the radius r of the outer edge of the land 56 between the inner and outer ports, and the inner edge 59 of the posts 55' correspond to arcs having a radius r equal to the radius of the inner edge of the land 56. The circumferential length of the ports 55' will vary dependent upon the angular space between adjacent ones of the ports 55' and can be increased if the ports are moved radially outwardly from the center.

Each of the ports 55 in the inner gear is communicated with a respective one of the displacement chambers between the teeth and the inner and outer gears. These passages are advantageously located within the inner gear, although it is to be understood that similar passages could be formed in the stationary housing and arranged to communicate with the rotor ports 55 as the inner gear moves in an orbital path. In order to effect valving of the fluid displacement chambers between the inlet and out-let ports 45 and 51 at the transition points between expansion and contraction of the (chambers, the passages 65 are arranged so as to communicate each rotor port 55 with a fluid displacement chamber that is angularly spaced approximately 90 from the respective rotor port. Thus, the rotor passage designated 65a in FIG. 2 communicates with the fluid displacement chamber at the full mesh point of the gears and extends around through substantially 90 to a port designated 5511. When the shaft 3 1 is rotated in the direction indicated by the arrow in FIG. 2, the rotor port 55a will move into full communication with the inlet port 4 5 in the housing as the displacement chamber with which the passage 65a communicates progres sively expands to draw fluid thereinto. To pump fluid from the inlet port 4 5 to the outlet port 51, each of the passages 65 must communicate with a fluid displacement chamber which angularly leads the respective rotor port 55 by approximately 90.

When a relatively large number of teeth are provided on the inner and outer gears, it is preferable to axially space certain ones of the spiralling passages 65 from each other to enable the use of relatively larger crosssections in the passages. As shown herein, alternate ones of the passages '65 are formed in opposite end faces of the inner gear 1 9 and end plates 67 and 68 are afiixed as by brazing to the ends of the inner gear to seal the passages 65. The aforedescribed ports 55 extend through at least that end plate 68 which abuts against the inlet and discharge ports 45 and 51.

The gear set including the outer gear 10 and the inner gear 18 are arranged to draw fluid from a plurality of separate sources, such as the 'aforedescn'bed sumps 24, 25 and 25. As shown in phantom lines in FIG. 3, the end face of the head 14 has an annular inner port 71 and a plurality of annularly spaced outer ports 72 which are located radially outwardly from the inner port and separated by a sealing land 73. The inner gear 13 has valve ports75 which open at the end face thereof and which move between the inner and outer ports 71 and 72 in the head 14 as the inner gear moves in an orbital path. The inner gear 18 is the same as the gear 19 and the ports 75 have a diameter slightly less than the width of the land 73 between the inner and outer ports 71 and 72 and are located on a circle corresponding to the mean radius of the land. However, in order to effect pumping of fluid from the separate outer ports 72 and to discharge the fluid to the inner port 71, the passages 78 which communicate the rotor ports with the displacement chambers are arranged to extend in a direction opposite the direction of rotation of the shaft 31. Consequently, the displacement chamber with which each passage 73 communicates lags the respective valve port 75 by approximately as shown in FIG. 3.

The gear set including the outer gear 10 and inner gear 15 are adapted to draw fluid in from a plurality of sources corresponding in number to the number of teeth on the outer gear, and the number of teeth can be varied, within limits, to accommodate various different numbers of supply sources. However, when the number of sources is relatively low, it is frequently advantageous to intercomrnunicate alternate ones of the ports 72 so as to provide more uniform flow. As specifically shown herein, three collector chambers designated 81, 82 and 83 are provided in the head 16 and are closed at their outer ends by a cap 84. The collector chambers 81-83 communicate through generally radially extending passages 86, 87 and 88 respectively, with conduits 91-93 leading to the sumps 25, 24 and 26. Passages 94 in the head 14 communicate every third one of the outer ports 75 with the collector chamber 81 and passages 95 and 96 similarly communicate different ones of the outer passages 75 with the collector chambers 82 and 83 respectively. Thus, each time the inner gear 18 is moved through one com plete orbit, five diiferen-t ones of the fluid displacement chambers draw fluid in from each of the collector chambers 81-83 and the surnps associated therewith. The fluid is discharged to a common outlet chamber 101 in the head and through an outlet passage 102 and conduit 103 to an air separator and accumulator chamber 104. Fluid from the accumulator chamber is passed through conduit 49 to the inlet of the other gear set for distribution to the several outlets.

As the inner gear moves in an orbital path relative to the outer gear, in the direction indicated by the arrows in FIGS. 2 and 3, the inner gear will turn about its own axis through angle corresponding to the angular spacing between adjacent teeth. The rotor ports such as 55 shown in phantom in FIG. 5 will consequently move through a hypotrochoidal path designated T in FIG. 5. The line T in FIG. 5 shows the path of the center of the rotor ports, as the inner gear moves through fifteen orbits corresponding in number to the number of teeth in the outer gear. It is to be noted that the rotor port path has cusps as it moves toward each of the outer ports 51, and which cusps are advantageous in that they provide 'sjoaie a prolonged dwell period over each outlet port. Since the relative rotation between the inner and outer gears is controlled and is equal to one tooth space of the inner gear for each orbit thereof, each of the displacement chambers discharges its full volume into a respective one of the ports so as to, in eflect, function as a plurality of separate pumps. This is particularly advantageous in a lubrication system, since, if anyone of the outlet passages 27 is restricted due to toreign matter, the pressure generated in the pump as each discharge compartment discharges thereinto will build up and tend to clear out the restriction.

The pumping apparatus shown in FIGS. 7 and 8 is generally the same as that shown in FIGS. 1-5 and like numerals, followed by the superscript are used to designate corresponding parts. Thus, the outer gear 11 is connected to spaced Walls 12' and 13 by studs 15' and sealed thereto as by O-rin-gs 17'. The inner .gear 19 is disposed within the outer gear and has one end thereof in wiping engagement with the end face of the head 13'. Inner and outer annular ports 45 and 51' are formed in the head and communicate with passages 46 and 52'. The inner gear has port passages 55" formed therein and opening at the end face thereof and which passages communicate through spiral rotor passages 65 with the fluid displacement chambers. A modified drive is provided for connecting the shaft 31' to the inner gear. As shown, the inner gear is formed with internal teeth 125 disposed concentric With the axis of the inner gear, and the shaft has external teeth 126 disposed concentric with its own axis. The pitch diameter of the teeth 125 on the shaft 31 is made less than the pitch diameter of the internal teeth 125 in the gear 19' by an amount equal to twice the eccentricity between the inner and outer gears. so that the inner gear can orbit around the gear teeth 126 as the inner gear orbits within the outer gear 11. This provides an eflicient and compact speed changing arrangement. As the inner gear orbits, the outer shaft will turn through an angle determined by the difference in the number of teeth in the gears 125 and 126, and in the angular spacing between adjacent teeth on the inner gear. In the form shown, fifteen inner teeth 125 are provided on the gear 19' and mesh with fourteen teeth 126 on the shaft. Since the ratio of the number of teeth on the outer and inner gears 11' and 19 is also 15-14, this inner gear will move through seven orbits for each revolution of the shaft 31'.

As is apparent, the drive shafts can be rotated in either direction to enable reversal of the direction of flow through the gear sets when operated as a pump. Thus, the gear set 10, 18 herein shown as a multiple inlet pump, can also be operated as a multiple discharge pump in which event the flows from every third port are confined to provide a more uniform stream. Moreover, the device may also be operated as fluid motors by supplying fluid under pressure thereto to thereby drive the shaft 31.

I claim:

1. A pump or motor comprising, a housing having an internally toothed outer gear member and end walls at opposite ends of the outer gear member defining a pump chamber, said end walls having inlet and discharge port means therein concentric with said outer gear member and spaced radially apart, fluid supply and discharge passage means respectively communicating with said inlet and discharge port means, a toothed inner gear member having one tooth less than the outer gear member and movable in an orbital path relative to said outer gear member, the teeth on said inner and outer gear members being shaped so that each of the teeth on the inner gear member engage and form a running seal with the teeth on the outer gear member in all relative positions of said inner and outer gear members to define a plurality of segregated pumping compartments in said chamber which expand and contract as said inner gear member moves in said orbital path relative to said outer gear member, a shaft having an eccentric driving connection to said inner gear member, said inner gear member having a plurality of annularly spaced rotor ports opening on at least one end face, a plurality of valve passage means corresponding in number to the number of said pumping compartments and communicating each rotor port with a respective one of the pump compartments that is angularly spaced around said inner gear member approximately from that rotor port, said rotor ports being movable with said inner gear member in a hypotrochoidal path that alternately intersects the radially spaced inlet and discharge port means at the radially inner and outer portions of the path to alternately communicate said rotor ports with said inlet and discharge port means in timed relation with the cyclic change in volume of the pumping compartments.

2. The combination of claim 1 wherein said rotor ports extend completely through said inner gear member and open at both ends of the inner gear member.

3. The combination of claim 1 wherein said eccentric driving connection includes an eccentric cam on said shaft rotatably connected to said inner gear member.

4. The combination of claim 1 wherein said eccentric connection includes internal gear teeth on said inner gear member and external gear teeth on said shaft disposed in meshing engagement with said internal gear teeth on said inner gear member to rotate the shaft about its axis as the inner gear moves orbitally around the shaft.

5. A pump or motor comprising, a housing having an internally toothed outer gear member and end walls at opposite ends of the outer gear member defining a pump chamber, said end walls having inlet and discharge port means therein concentric with said outer gear member and spaced radially apart, fluid supply and discharge passage means respectively communicating with said inlet and discharge port means, a toothed inner gear member hav-, ing one tooth less than the outer gear member and movable in an orbital path relative to said outer gear member, the teeth on said inner and outer gear members being shaped so that each of the teeth on the inner gear member engage and form a running seal with the teeth on the outer gear member in all relative positions of said inner and outer gear members to define a plurality of segregated pumping compartments in said chamber which expand and contract as said inner gear member moves in said orbital path relative to said outer gear member, a shaft having an eccentric driving connection to said inner gear member, said inner gear member having a plurality of annularly spaced rotor ports opening on at least one end face, said inner gear member having a plurality of valve passage means therein corresponding in number to the number of said pumping compartments and communicating each rotor port with a respective one of the pump compartments that is angularly spaced around said inner gear member approximately 90 from that rotor port, said rotor ports being movable with said inner gear member in a hypotrochoidal path that alternately intersects the radially spaced inlet and discharge port means at the radially inner and outer portions of the path to alternately communicate said rotor ports with said inlet and discharge port means in timed relation with the cyclic change in volume of the pumping compartments.

6. The combination of claim 5 wherein said inner gear includes a central body having valve passage means formed in opposed sides thereof and end plates overlying the ends of said body to close said valve passages, said rotor ports being formed in at least one of said end plates.

7. A multiple discharge pump or motor comprising, a housing having an internally toothed outer gear member, end walls at opposite ends of the outer gear member defining a pump chamber, said end Walls having an outlet port means including a plurality of separate outlet ports arranged in a circle concentric with said outer gear member and an inlet port means concentric with said outlet port means and spaced radially therefrom, a plurality of separate discharge conduits each communicating with different ones of said outlet ports to provide segregated fiows, inlet conduit means communicating with said inlet port means to supply fluid thereto, an externally toothed inner gear member having one tooth less than said outer gear member and movable in an orbital path relative to said outer gear member, the teeth on said inner and outer gear members being shaped to engage and form a running seal in all relative positions of said inner and outer gear members to define a plurality of segregated pumping compartments in said chamber which expand and contract as said inner gear member moves in said orbital path relative to said outer gear member, shaft means operatively connected to said inner gear member, said inner gear member having a plurality of rotor ports opening at least at one end of said inner gear member, a plurality of passage means corresponding in number to the number of said pumping compartments and communicating each rotor port with a respective one of the pumping compartments that is angularly spaced around the inner gear member approximately 90 from that rotor port, said rotor ports being movable with said inner gear member in a hypotroohoidal path that alternately intersects the radially spaced inlet and outlet port means at the radially inner and outer portions of the path to alternately communicate each rotor port with said inlet port means and said separate outlet ports in timed relation with the cyclic change in volume of the pumping compartments.

8. A pump comprising a housing having an internally toothed outer gear member and wall means at opposite ends of the outer gear member defining a pump chamber, one of said wall means having a first port means therein including a set of ports corresponding in number to the number of teeth in said outer gear and arranged in an annular path concentric with said outer gear member, said one of said wall means having a second port means spaced radially from said first port means, inlet passage means communicating with one of said port means and outlet passage means communicating with the outer of said port means, an externally toothed inner gear member having teeth shaped to engage the teeth on the outer gear member in all relative positions of the inner and outer gear members to define a plurality of segregated pumping compartments in the chamber, said inner gear member being mounted for movement in an orbital path relative to said outer gear member and having one tooth less than the outer gear member whereby the inner gear member turns about its axis a distance corresponding to the angular spacing between adjacent teeth thereon each time it moves through a complete orbit and in a direction opposite the direction of orbital movement, a rotary shaft having an eccentric connection to the inner gear member for driving the same in an orbital path relative to the outer gear member to cyclically vary the volume of the pumping compartments, said inner gear member having an end face slidably abutting said one of said end walls, a set of valve ports in said end face corresponding in number to the number of teeth on the inner gear and arranged in a circle concentric with the inner gear, said valve ports being movable in a hypotrochoidal path alternately between said second port means and each of the ports of said first port means, and passage means in said inner gear member communicating each of the valve ports with a respective one of the displacement chambers that is angularly spaced around the inner gear member approximately 90 from that port.

9. The combination of claim 8 wherein said ports of said first port means are spaced radially outward from said second port means. I

10. The combination of claim 9 wherein one of said inlet and outlet passage means includes a plurality of separate conduits each individual to one of said ports in said first port means.

11. The combination of claim 9 wherein one of said inlet and outlet passage means includes a plurality of separate conduits and means communicating each conduit with alternate ones of said ports of said first port means.

12. A multiple discharge pump comprising a housing having spaced end walls and defining a pump chamber, an internally toothed outer gear member :and an externally toothed inner gear member disposed in said chamber, said inner and outer gear members being eccentric to each other and said inner gear member having one tooth less than the outer gear member, one of said gear members being movable in an orbital path relative to the other gear member and the teeth on said inner and outer gear members being shaped so that each of the teeth on the inner gear member engages and forms a running seal with the teeth on the outer gear member in all relative positions of said inner and outer gear members to define a plurality of segregated pumping compartments in said chamber which expand and contract in volume as said one of said gear members moves in said orbital path relative to said other of said gear members, said end walls having an outlet port means including a plurality of annularly spaced outlet ports arranged in a circle concentric with said other gear member, said end walls having an inlet port means therein spaced radially from said first port means, a plurality of separate outlet fiow conduits communicating with different ones of said ports of said outlet port means to provide segregated discharge flows, said one of said gear members that is movable in an orbital path having a plurality of rotor ports opening at least at one end of the gear member, passage means communicating each of said ports in said one of said gear members with a respective one of said pumping compartments which is angularly spaced around said one of said gear members approximately from that port, said rotor ports being movable in a hypotrochoidal path that alternately intersects the radially spaced inlet and outlet port means at the radially inner and outer portions of said path to alternately communicate said rotor ports with said inlet and discharge ports in timed relation with the cyclic change in volume of the pumping compartments.

13. A multiple discharge pump comprising a housing having spaced end walls and defining a pump chamber, an internally toothed outer gear member and an externally toothed inner gear member disposed in said chamber, said inner and outer gear members being eccentric to each other and said inner gear member having one tooth less than the outer gear member, one of said gear members being movable in an orbital path relative to the other and the teeth on said inner and outer gear members being shaped so that each of the teeth on the inner gear member engages and forms a running seal with the teeth'on the outer gear member in all relative positions of the inner and outer gear members to define a plurality of segregated pumping compartments in said chamber which expand and contract in volume as said one of said gear members moves in said orbital path relative to the other of said gear members, said end walls having outlet port means including a plurality of annularly spaced ports arranged in a circle, said end walls having inlet port means therein, one of said gear members having valve ports in at least one end thereof and passage means for communicating each valve port with a respective one of the pumping compartments between the inner and outer gear members, said valve ports in said one of said gear members being movable therewith alternately into communication with said inlet port means and the individual outlet ports in timed relation with the cyclic change in volume of the pumping compartments to discharge the fiuid from each pumping compartment to one of said outlet ports, and a plurality of separate discharge conduits connected to difierent ones of said outlet ports to deliver divided flow firom the pump.

14. A pump or motor comprising, a housing having a stationary internally toothed outer gear and inlet and discharge ports, an externally toothed inner gear disposed in meshing engagement with said outer gear and defining a plurality of fluid displacement chambers therebetween, said inner gear being mounted for movement in an orbital path within the outer gear to cyclically vary the volume of said displacement chambers and having one tooth less than the outer gear whereby the inner gear turns about its axis through an angle corresponding to the angular spacing between the teeth on the inner gear each time the inner gear moves through a complete orbit and in a direction opposite the direction of orbital movement, valve means for controlling the flow between each of said displacement chambers and the inlet and discharge passages in timed relation with the cyclic variation in the volumes of said displacement chambers, said inner gear having an internally toothed opening therein concentric with :said inner gear, and a shaft extending into said opening concentric with the outer gear, said shaft having an externally toothed gear thereon meshing with said internally toothed opening, said teeth on said shaft having a pitch diameter smaller than the pitch diameter 10 of the teeth in the internal opening by an amount substantially equal to twice the eccentricity between the inner and outer gears.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3 10:6 163 October 8, 1963 Bruce H Mosbacher bove numbered patrror appears in the a 11d read as ertified that e the said Letters Patent show It is hereby o d that ent requiring correction an corrected below.

Column 7 line 38 for outer read other Signed and sealed this 7th day of April 1964 EDWARD J BRENNER (SEAL) Attest: 

1. A PUMP OR MOTOR COMPRISING, A HOUSING HAVING AN INTERNALLY TOOTHED OUTER GEAR MEMBER AND END WALLS AT OPPOSITE ENDS OF THE OUTER GEAR MEMBER DEFINING A PUMP CHAMBER, SAID END WALLS HAVING INLET AND DISCHARGE PORT MEANS THEREIN CONCENTRIC WITH SAID OUTER GEAR MEMBER AND SPACED RADIALLY APART, FLUID SUPPLY AND DISCHARGE PASSAGE MEANS RESPECTIVELY COMMUNICATING WITH SAID INLET AND DISCHARGE PORT MEANS, A TOOTHED INNER GEAR MEMBER HAVING ONE TOOTH LESS THAN THE OUTER GEAR MEMBER AND MOVABLE IN AN ORBITAL PATH RELATIVE TO SAID OUTER GEAR MEMBER, THE TEETH ON SAID INNER AND OUTER GEAR MEMBERS BEING SHAPED SO THAT EACH OF THE TEETH ON THE INNER GEAR MEMBER ENGAGE AND FORM A RUNNING SEAL WITH THE TEETH ON THE OUTER GEAR MEMBER IN ALL RELATIVEPOSITIONS OF SAID INNER AND OUTER GEAR MEMBERS TO DEFINE A PLURALITY OF SEGREGATED PUMPING COMPARTMENTS IN SAID CHAMBER WHICH EXPAND AND CONTRACT AS SAID INNER GEAR MEMBER MOVES IN SAID ORBITAL PATH RELATIVE TO SAID OUTER GEAR MEMBER, A SHAFT HAVING AN ECCENTRIC DRIVING CONNECTION TO SAID INNER GEAR MEMBER, SAID INNER GEAR MEMBER HAVING A PLURALITY OF ANNULARLY SPACED ROTOR PORTS OPENING ON AT LEAST ONE END FACE, A PLURALITY OF VALVE PASSAGE MEANS CORRESPONDING IN NUMBER TO THE NUMBER OF SAID PUMPING COMPARTMENTS AND COMMUNICATING EACH ROTOR PORT WITH A RESPECTIVE ONE OF THE PUMP COMPARTMENTS THAT IS ANGULARLY SPACED AROUND SAID INNER GEAR MEMBER APPROXIMATELY 90* FROM THAT ROTOR PORT, SAID ROTOR PORTS BEING MOVABLE WITH SAID INNER GEAR MEMBER IN A HYPOTROCHOIDAL PATH THAT ALTERNATELY INTERSECTS THE RADIALLY SPACED INLET AND DISCHARGE PORT MEANS AT THE RADIALLY INNER AND OUTER PORTIONS OF THE PATH TO ALTERNATELY COMMUNICATE SAID ROTOR PORTS WITH SAID INLET AND DISCHARGE PORT MEANS IN TIMED RELATION WITH THE CYCLIC CHANGE IN VOLUME OF THE PUIMPING COMPARTMENTS. 